The present invention relates generally to solenoids and actuators.
Many engine lubrication systems manufactured today include an oil level sensor that senses the level of oil in a reservoir, e.g., an oil pan, that is part of the system. If the oil level in the reservoir falls below a critical level, the operator is advised, e.g., by an indicator light, that oil must be added to the engine lubrication system. Thus, the operator must either add the oil to the engine or have a service technician, e.g., a mechanic, do so.
In addition to the oil level sensor, some engine lubrication systems include an oil condition sensor that senses the condition of the engine oil based on an oil parameter, e.g., oil dielectric constant. If the condition of the oil deteriorates below a predetermined threshold, the operator is instructed, e.g., by an indicator light, to either change the oil or add a chemical additive to the oil in order to enhance the condition of the oil. In either situation, the engine must be temporarily removed from operation so that someone, e.g., a mechanic, can manually service the engine in order to change the engine oil, add fresh oil to the engine oil, or add a chemical additive to the engine oil. To avoid extended down time while the engine is being serviced, an on board system can be used to automatically provide fresh oil or a chemical additive to the lubrication system. Such a system requires a device that can automatically administer a required amount of fresh oil or chemical additive in an accurate and controllable manner.
It happens that fluid dosage devices for automatically dispensing fluid, e.g., oil, have been provided for use in conjunction with two-stroke engines. These devices typically include gear driven pumps that dispense a predetermined dose of oil to the fuel mixture or directly to parts within the engine in need of lubrication, e.g., crank bearings. A crank shaft or transmission shaft are typically used to drive these devices. Thus, as recognized by the present invention, it is difficult to accurately control when the oil is dispensed to the engine. Moreover, the present invention recognizes that it is difficult to accurately control the amount of fluid dispensed.
As such, the present invention has recognized these prior art drawbacks, and has provided the below-disclosed solutions to one or more of the prior art deficiencies.
A fluid dispensing solenoid valve includes a plunger tube that forms a first inlet orifice and a first outlet orifice. A plunger that forms a fluid chamber is slidably disposed relative to the plunger tube. The plunger is movable between a fluid fill configuration, wherein the fluid chamber communicates with the inlet orifice to allow the fluid chamber to be filled and a fluid dump configuration, wherein the fluid chamber communicates with the outlet orifice to allow the fluid chamber to be emptied.
In a preferred embodiment, the valve includes a source reservoir that is in fluid communication with the inlet orifice. Moreover, the source reservoir communicates with the fluid chamber when the plunger is in the fluid fill configuration. Preferably, the valve also includes a target reservoir that is in fluid communication with the outlet orifice. The target reservoir also communicates with the fluid chamber when the plunger is in the fluid dump configuration.
In a preferred embodiment, the valve includes a coil that surrounds the plunger. The coil is energizable in order to bias the plunger between the fluid fill configuration and the fluid dump configuration. Preferably, the valve includes a housing that surrounds the coil. In one aspect of the present invention, the source reservoir is a stand-alone source reservoir. In another aspect, the source reservoir is an integrally formed source reservoir that is integrally formed with the sensor between the plunger tube and the housing.
Preferably, the plunger tube forms a second outlet orifice and the valve includes a vent tube that is connected to the second outlet orifice. The vent tube allows the fluid chamber to vent as it is filling. The plunger tube also forms a second inlet orifice and the vent tube is also connected to the second inlet orifice to allow the fluid chamber to vent as it is emptying.
Preferably, the fluid dispensing solenoid valve is in fluid communication with an engine oil pan to provide fluid to the engine oil pan when the valve is in the fluid dump configuration. The solenoid valve may also be used to provide fluid to a fluid based transmission or a hydraulic machine.
In yet another aspect of the present invention, a system for dispensing a predetermined quantity of fluid to an engine oil pan includes an engine, an oil pan, and a fluid dispensing solenoid valve in fluid communication with the oil pan. The solenoid valve is energizable to dispense a predetermined quantity of fluid to the oil pan.